My biggest disapointment is that we didn't get to see more of what could have happened. I mean he did accept her in the end of S1 and one and they both confessed their love for each other...more would have been lovely.

This would have been nice. Maybe she could have taught him that he can't kill a demon with a gun. I'm just getting to the end of season 1 for the million time and I being reminded how much I like them together and I also have to laugh that he kept pulling his gun to fight a demon. If we was around longer he would have learned. I wonder if he would have adapted the mindset that Daryl had.